Van Himbeeck, Jim
[UCL]
Papalexandris, Miltiadis
[UCL]
Habotte, Nicolas
[UCL]
In the turbofan engines, flutter is an aeroelastic instability involving a self-excited vibrational behavior of the blades in the compressors and turbines which causes blade failure due to high-cycle fatigue. This master thesis studies the sensitivity of flutter stability to geometrical parameters in a transonic compressor and has been carried out partially during an internship at Safran Aero Boosters (SAB) and in collaboration with the Von Karman Institute (VKI). The work produced with SAB consists of a preliminary study for the reduction of the computational requirements of flutter CFD simulations. The limitations of the current strategies are presented followed by the new computational parameters (spatial and time discretizations) which allow to reduce the convergence time of the calculations by a factor of 4 and the CPU costs by 2. However a degradation in the prediction accuracy of flutter is found. An independent study is performed with the VKI to analyze the influence of blade sweep on the flutter behavior of the NASA Rotor 67. First the geometry of the blade is reproduced in a parametrized fashion, allowing to create the new geometries with different blade sweeps. Flutter simulations are then performed on the various geometries and it is shown that the flutter stability of the blade is strongly affected by sweep.
Bibliographic reference |
Van Himbeeck, Jim. Flutter sensitivity to rotor blade geometry in transonic compressors. Ecole polytechnique de Louvain, Université catholique de Louvain, 2020. Prom. : Papalexandris, Miltiadis ; Habotte, Nicolas. |
Permanent URL |
http://hdl.handle.net/2078.1/thesis:27634 |